Matrix register file and extended subwords: two techniques for embedded media processors

In this paper we employ two techniques suitable for embedded media processors. The first technique, extended subwords, uses four extra bits for every byte in a media register. This allows many SIMD operations to be performed without overflow and avoids packing/unpacking conversion overhead because of mismatch between storage and computational formats. The second technique, the Matrix Register File (MRF), allows flexible row-wise as well as column-wise access to the register file. It is useful for many block-based multimedia kernels such as (I)DCT, 2 × 2 Haar Transform, and pixel padding. In addition, we propose a few new media instructions. We employ Modified MMX (MMMX), MMX with extended subwords, to evaluate these techniques. Our results show that MMMX combined with an MRF reduces the dynamic number of instructions by up to 80% compared to other multimedia extensions such as MMX.

• Type: Conference
• Year: 2005
• Where: CF
• Authors: Asadollah Shahbahrami, Ben H. H. Juurlink, Stamatis Vassiliadis
• Keywords: Applied Computing, Avoids Packing/unpacking Conversion, CF 2005, Embedded Media Processors, Matrix Register File